-LRB- CNN -RRB- -- Mad cow disease , SARS and now swine flu : Some diseases grab the headlines . But thousands of people worldwide suffer from very rare conditions , many of which few people have ever heard of .

England 's King George III may have suffered from porphyria , a disorder that affects the nervous system .

From the Alice in Wonderland syndrome that might have inspired Lewis Carroll , to the disease that may have sent an English King mad , we take a look at some of these obscure illnesses .

Morgellons

According to the Morgellons Research Foundation , crawling , biting and stinging sensations and the emergence of strange blue , black or red fibers from the skin characterize a disease that nearly 14,000 people suffer from , according to the Foundation .

This is often accompanied by exhaustion , short-term memory loss , joint pain and changes in vision . The condition was named Morgellons in 2002 by a mother who believed her two-year-old son was suffering from the disease . The name comes from a 17th century skin condition found in France , in which children died after the emergence of ` dark hair . '

However , there is much debate over whether the condition actually exists .

In March 2008 , the Journal of Dermatologic Therapy reported that most doctors believe it to be form of delusion , in which sufferers falsely believe they are infected with parasites . Consequently , the fibers in the skin are thought to be textile-based , picked up by oozing scabs resulting from more common conditions such as eczema or scabies .

The U.S. based Center For Disease Control and Prevention recently announced it would investigate the disease after an increased number of inquiries from the public .

See photos of people living with rare diseases ''

Progeria

Progeria is congenital , meaning a defect or damage to a fetus . Sufferers of this fatal illness have a striking appearance resembling premature ageing , but die at an average age of 13 .

Profound growth delays begin at between nine and 24 months , leading to abnormal facial developments such as a disproportionately small face , bulging , prominent eyes and an underdeveloped jaw . By the age of two , hair from the scalp , eyebrows and eyelashes is lost .

The U.S. National Organization of Rare Disorders -LRB- NORD -RRB- says sufferers eventually lose the layer of fat beneath the skin and , in time , elasticity is lost in artery walls , leading to fatality via heart attack or stroke in 90 percent of sufferers .

Water allergy

Known to have ever affected only 30 people , water allergy or `` aquagenic urticaria '' is extremely rare , but its existence has been confirmed by the Medical Review Board . Sufferers appear to be allergic to water . It usually occurs late in life and often as a consequence of a hormonal imbalance brought about by giving birth .

A case emerged in the UK in April this year , leaving a 21-year-old mother unable to drink water or get caught in the rain because her skin develops a painful burning rash . She can shower for a maximum of 10 seconds per week and can drink only Diet Coke . It is not strictly an allergy but a hypersensitivity to the ions found in non-distilled water .

Foreign accent syndrome

Sufferers of foreign accent syndrome inexplicably find themselves talking in an unrecognizable dialect . Only 60 cases have ever been recorded .

Doctors initially dismissed it as a psychiatric problem , but in 2002 , scientists at Oxford University , England , observed that sufferers shared the same brain abnormalities , which led to changes in speech pitch , lengthening of vowel sounds and other irregularities .

According to the Journal of Neurolinguistics , sufferers do n't necessarily have to have been exposed to the accent they adopt : their new voice is not , strictly speaking , a foreign accent , but the changes in speech often bear a striking resemblance to other world accents .

The first case concerned a Norwegian woman in 1941 , who developed a strong German accent and was ostracized from her community .

Laughing Death

Laughing Death , more commonly known as Kuru , was exclusive to the tribal Fore people of New Guinea . The disease , which was characterized by sudden bursts of maniacal laughter , hit the headlines in the 1950s and drew in doctors from around the world .

U.S. and Australian physicians observed men and women with shaking limbs , which subsided with rest , but a month to three months later sufferers would begin to sway and stumble , lose the ability to stand , become cross-eyed and lose the power of coherent speech before eventually dying .

The National Institute of Neurological Disorders and Stroke reported that tests on the deceased showed death had been caused by the emergence of holes in the brain , known as `` swiss-cheesing . ''

Eventually the U.S. physician Carleton Gajdusek worked out that the infection was being passed on through the village custom of eating family members after death . When cannibalism was eliminated , the epidemic came to an end . In 1976 , Gajdusek was awarded the Nobel Prize for his work .

Fibrodysplasia ossificans progressiva -LRB- FOP -RRB-

In 1938 , when American Harry Eastlack was five-years-old , he broke his leg . The fracture did n't set properly , his hip and knee stiffened up and , bizarrely , bone growths developed on the muscles of his thigh . By his mid 20s , the vertebrae of his back had begun to fuse together . When he died aged 39 in 1973 , he was able to move only his lips .

He suffered from fibrodysplasia ossificans progressiva -LRB- FOP -RRB- , a rare disease affecting some 1 in 2 million people , in which the body 's tendons and ligaments undergo a strange metamorphosis , essentially a transformation into bone .

The condition is congenital and characterized by a malformation of the big toe that is present at birth . Eastlack donated his skeleton to research of the disease , and it is on display at the Mutter Museum in Philadelphia . The International FOP Association continues to research this extremely rare condition .

Alice in Wonderland syndrome

According to the Oxford Handbook of Clinical Medicine , sufferers of Alice in Wonderland syndrome perceive objects as being far smaller than they are . The condition , also known as micropsia or Lillliput sight , can also affect the sense of hearing , touch and perceptions of one 's own body image . Learn more about rare disorders ''

The syndrome is associated with migraine headaches and named after Lewis Carroll 's Alice 's Adventures in Wonderland , in which Alice goes through many bizarre experiences similar to those which might be experienced by a micropsia sufferer . The fact that Carroll suffered from migraines is well documented , and some speculate that his suffering may have prompted many passages in the work .

Porphyria

Purple urine and feces make porphyria infamous , as does the fact that the `` mad '' 18th century English King George III may have suffered from it . Porphyria leads to complications in the production of ` heme , ' a protein vital to red blood cells , and affects the skin and nervous system . Attacks lead to abdominal pain , stomach cramps , nausea , vomiting and constipation .

NORD lists other symptoms including increasing sensitivity to the sun , itching and swelling . Increased hair growth on the forehead may also occur .

Toxins resulting from the failed heme production can affect the coloring of other areas , especially after exposure to sunlight . Sometimes the teeth and fingernails can adopt a reddish appearance . It is these toxins that lead to the dark urine and feces .

Mary Queen of Scots , Vincent Van Gogh , and King Nebuchadnezzar of Babylon may have suffered from this disease .

Pica

The magpie , Latin name pica , will eat anything , and so will sufferers of pica syndrome . Almost always pregnant women or children , sufferers develop an appetite for non-nutritive substances , such as paint , clay , plaster or dirt , or alternatively items that are more commonly considered to be food ingredients , such as raw rice , flour or salt .

It can only be considered pica if the appetite persists for over a month and the sufferer is of an age where eating these objects is considered developmentally inappropriate . Medical researchers have tenuously linked pica with a mineral deficiency , but according to the National Organization for Rare Disorders , experts have yet to nail down a real , firm cause or cure for this strange disorder .

Moebius syndrome

Moebius is extremely rare , genetic and characterized by complete facial paralysis . Sufferers can not close their eyes , look from side to side , or form facial expressions . Limb abnormalities such as clubbed feet and missing fingers are often also present .

According to the Moebius Syndrome Foundation , most cases are isolated , with no notable family history , and sufferers go on to lead long and healthy lives .

Family members often learn to recognize body language , posture and vocal tone as communicators of emotion , and sometimes claim they forget the person has facial paralysis altogether .

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A look at some of the rarest diseases in the world

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Morgellons sufferers say strange fibers emerge from their bodies

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Others like Progeria sees the aging process accelerate much faster than usual